Optometer.



No. 803,267. PATENTED 0013.31, 1905. L. e. BOOTH.

' OPTOME'IER,

APPLICATION FILED DEG.6, 1904.

UNITED STATES .PATENT )FFICE.

' LoUIs e. BOOTH, or CHICAGO, ILLINoIs.

OPTOMETEFL' Specification of Letters Patent.

Patented Oct. 31, 1905.

Application filed December 6, 1904. Serial No. 235,713.

To all whom it Worry concern:

Be itknown that I, LOUIS Gr. BOOTH, of Chicago, in the county of Cookand State of Illinois, have invented certain new and useful Improvementsin Optometers; and I do hereby declare that the following is a full,clear, and

exact description thereof,.reference being had to theaccompanyingdrawings, and to the letters of reference marked thereon,which form a part of this specification This invention relates toimprovements in optometers, and refers more specifically to that classof optometers which are so constructed as to be capable of being foldedtogether in small compass for convenience in transportation, moreparticularly by mail, and which may be made at such low cost as toprofitably permit of its production and sale for a single use thereof.

The device herein shown is more particularly applicable for use byopticians who vend eyeglasses and spectacles through correspondence, bymail or otherwise, and who do not, therefore, have access to theircustomers for the purpose of testing their vision by the use of theusual more permanent devices employed by the opticians when personallymaking examinations of this kind. In a device of this character it isimportant that it be produced at low cost, that it may be packed insmall compass for transportation, preferably by mail, and particularlywhen set up for use that it possess such stability as to insure accuracyof measurement, and thereby enable a prospective customer, under thedirection supplied by the optician, to furnish such measurements as willenable the optician to furnish the customer with the lenses required. Insuch use of the device it will ordinarily be used but once. must be ofsuch stability as to be accurate, while capable of being produced at alow cost.

My device, while primarily designed for individual customers, is of suchconstruction as to permit of its satisfactory use by Opticians whosebusiness does not warrant the purchase of a more elaborate outfit.

One object of the invention, therefore, is to provide a scale-strip foroptometers which is so arranged and to which the target and lensholderare so applied that said holder and target are held in reliablepositions, so that the lens shall always occupy a predetermined relationto the target.

A further object of the invention is to hold the lens and target in suchrelation to the strip For this reason the device that the scale may beclearly read while the test is being made and whereby also the target isof such stability that it will remain in any position on thescale-strip, thereby insuring accuracy of the test.

Another object of the invention is to provide a suitable detachableconnection between the lens-holder and the scale-strip of such characterthat it holds the lens-holder in reliable angular relation to thescale-strip during use and which also permits ready detachmentthereoffrom the strip, so the lens-holder can be placed flatwise against thestrip when packed for transportation.

A further object of the invention is to provide an improved detachableconnection between the target and the scale-strip which permits theready removal of the target and the packing of the target flat againstthe strip.

The invention has for its object other features of improvement, whichwill hereinafter more fully appear.

The invention consists in the matters hereinafter set forth, and moreparticularly defined in the appended claims.

In the drawings, Figure lis a perspective view of an optometer embodyingan approved form of the invention. Fig. 2 is a detail of thescale-strip. Fig. 3 is a detail of the lensholder. Fig. 4 is a detail ofthe target.

A designates the scale-strip, usually made of cardboard or othersuitable thin material. Said strip is preferably arranged verticallyedgewise, as shown in Fig. 1. It is provided at one end with an opentransverse slit a, adapted to receive the lens-holder B, which latter isformed with a slit 6, opening downwardly and adapted to interlock withthe slitted part of the strip A in a manner to constitute a reliableconnection between the strip and holder and to maintain the holderpreferably at right angles to the strip. Said connection not only holdsthe holder against transverse displacement, but also prevents itshifting endwise of the scale-strip and further prevents verticaltilting of the holder to the scale-strip. Such construction constitutesa detachable connection of the holder to the strip and permits thelens-holder to be readily separated or detached from the strip and to beattached thereto in such manner that the lens-holder will at all timesbe maintained at right angles to the scale-strip and in fixedlongitudinal position to the scale a, which is marked on the strip. Thesaid lens-holder is made of a thin flat piece of material, conven- IIOiently cardboard, and when disconnected from the strip may be laidfiatwise against the strip for packing or transportation. The lensholderis preferably provided with a handle 6 for convenience in holding theoptometer in front of the eye. The lens-holder is provided with a lens 5which may be attached thereto in any suitable manner. Said strip A isprovided with a long slot a, in which a target G is adjustably held in amanner to slide ment of which at different distances from thedisconnected from the strip.

lens by different eyes indicates, by reference to the scale, theparticular defect of vision and the character of lens required to remedysuch defects of vision. The target is provided with a handle 0 forconveniently shifting it longitudinally of the strip. The lens is soadjusted to the graduated strip and the test matter on the target thatwhen such test matter is most clearly seen the position of the targetrelatively to the scale indicates to-the optician the kind of lens tosend to the customer to remedy the defect of vision. By swinging thetarget vertically until the face thereof is brought into substantiallyparallel relation with respect to the upper and lower sides of the slot0, the target may be withdrawn and When so disconnected from the strip,the target may be placed flatwise against the strip for convenience inpacking or transportation. Arubber band may be conveniently usedforholding the strip, lens-holder, and target together in transportationor when it is desired to carry the optometer in the pocket.

In the use of the device by an optician it is held-with the lens infront of one eye of the patient, with the strip directed forwardlytherefrom, and the other eye of the patient is closed or its visionotherwise obscured. A When in this position, the target is moved towardor away from the lens until the proper point on the scale is reached atwhich test matter on the target is most readily discerned. The patientwhen using the device himself holds it in the same manner, he holdingthe device steady by grasping the handle of the lensholder in one handand manipulating the target with the other hand.

It will be observed that by reason of the verticality of the scale-stripand the location of the scale at one side of the line of vision thescale may be easily read while the device is in use. This constructionand arrangement is of material advantage, because the Optician or thepatient can clearly and conveniently see the scale and determine therelative position I of the target in making a test.

Furthermore, there is no disturbance of the proper relative verticalarrangement of the lens and target, because the strip, although made ofthin material, is substantially rigid in a vertical direction.

An important resultant advantage of the detachable connection of thetarget and the lens and the detachable connection for the target is thathinge-joints are avoided and the parts are more firmly held in properrelation than is possible by hinge-joints. Another advantage is thatthese parts when detached and placed flatwise against each other are notsubject to stress in such manner as to tend to weaken the connections ofthe parts.

The above-described embodiment of my invention is merely illustrativeand not restrictive as to its scope. I do not wish, therefore, to belimited to such embodiment except as hereinafter made the subject ofspecific claims.

I claim as my invention- 1. In an optometer, a thin flat strip uponwhich is indicated a scale, a flat target made i of thin materialslidable on said strip, and a fiat lens-holder, said lens-holder andstrip be- 1 ing provided with parts lying severally within the planesthereof, and constituting interlocking connections to detachably holdthe lensholder rigidly in a prescribed relation to the strip.

2. An optometer comprising a thin flat strip upon which is indicated ascale, a target and a lens-holder, both made of fiat thin material, saidstrip and each the said target and holder being provided with partslying severally within the planes of said members of the device andconstructed to detachably and rigidly connect said target andlens-holder with the strip.

3.. In an optometer, a flat thin strip upon which is indicated a scale,a fiat lens'holder made also of thin material, said lens-holder andstrip being formed to provide interlocking parts constructed todetachably fix the holder in a prescribed angular relation to the strip,While permitting the holder and its associated part of said connectionto lie flatwise against one face of the strip.

4. An optometer comprising a flat thin strip upon which is indicated ascale, a lens-holder fixed thereto and a target also made of flat thinmaterial and having sliding engagement with said strip, said strip andtarget being formed to provide interlocking connections constructed todetachably fix the target in a prescribed angular relation to the stripwhile permitting the target and its associated part of said connectionto be removed from the terial on which is indicated a scale and alensholder made also of thin flat material and having slitted,detachable connection with the strip.

6. An optometer comprising a flat strip of thin material on which isindicated a scale, a lens-holder made of thin material, both of saidparts being slitted to form a detachable connection, whereby the stripand lens-holder may be connected in angular relation, and a targetadjustably connected to the strip.

7. In an optometer, the combination of a flat strip of thin material, alens-holder attached thereto, said strip having a longitudinal slottherein and a target fitting in said slot and slidable along the strip:

8. In an optometer, the combination of a strip of thin material, alens-holder attached thereto, said strip having a longitudinal slottherein and a target having slits therein for engaging the strip at theedges of the slot, whereby the target is adjustably connected to thestrip.

9. In an optometer, the combination of a flat strip of thin material, alens-holder, said strip having a longitudinal slot therein, and a targetfitting in said slot and slidable along the strip, and constructed to bereleased from the slot by angularly shifting the target endwiserelatively to the strip.

10. In an optometer, the combination of a strip of thin material, alens-holder attached thereto, said strip having a longitudinal slottherein and a target having slits therein for adapted to be turnedlengthwise of the slot to permit disengagement of the strip from saidslot.

11. In an optometer, the combination of a strip of thin material for ascale, a lens-holder made of thin material and detachably connected tothe strip, said strip having a slot therein, and a thin target havinginterlocking, detachable sliding engagement with said strip.

12. In an optometer, the combination with a flat vertically-disposedstrip made of thin material and having a scale on one of its verticalfaces, a lens-holder and a target extending laterally from and supportedon said strip and having detachable connection therewith by meansholding them in fixed angular positions relatively to said strip.

13. In an optometer, a thin flat strip having thereon a scale, a targeton the strip and a lensholder, said strip being provided with atransverse slit and the holder at one margin with a longitudinal strip,whereby said parts may be locked together in angular relation.

In testimony that I claim the foregoing as my invention I aflix mysignature, in presence of two witnesses, this 25th day of November, A.D. 1904.

LOUIS G. BOOTH.

Witnesses:

WILLIAM L. HALL, GEORGE R. WILKINS.

